नियतं कुरु कर्म त्वं कर्म ज्यायो ह्यकर्मणः। शरीरयात्रापि च ते न प्रसिद्धयेदकर्मणः ॥
Transliteration
niyatam kuru karma tvam karma jyayo hy akarmanah sarira-yatrapi ca te na prasiddhyed akarmanah
Translation
Perform your prescribed duty, for action is better than inaction. A man cannot even maintain his physical body without work.
Purport
In earlier Shlokas, Bhagvan Shri Krishna explained Arjuna Karma is essential for every living being and nobody can sustain even for a moment without doing anything. Even to maintain this body one has to do something. So not doing is not an option. You have to do something. So why not do something which is as per your nature. Here Bhagvan Shri Krishna points out that Arjuna since is a warrior hence to fight for justice, is his natural duty.
